Teen dies from too much caffeine, coroner says

Drinking an excessive amount of caffeine cost the life of a teenage boy from South Carolina. In the two hours before he collapsed in class at Spring Hill High School, Davis Allen Cripe had drunk a caffè latte, a large Diet Mountain Dew and an energy drink.
The 16-year-old died from a "caffeine-induced cardiac event causing a probable arrhythmia". according to Richland County Coroner Gary Watts. He had no pre-existing heart condition. How much caffeine is safe to consume?
The Food and Drug Administration said drinking more than 400mg (about 5 cups of coffee) could lead to increased heart rate, higher blood pressure, irregular heartbeat, tremors, nervousness, insomnia and panic attacks.